Gas supply coupling for a water heater

ABSTRACT

A gas supply coupling and method of assembly for the delivery of combustion gases to a combustion chamber of a heating device includes a crimp ring which provides a metal-to-metal seal between the gas supply tube and the gas supply line.

The present application is a continuation-in-part application of U.S. patent application Ser. No. 11/282,931, filed Nov. 18, 2005.

BACKGROUND OF THE INVENTION

The present invention relates to a gas supply coupling for delivering natural gas to a combustion chamber of a water heater.

Domestic water heaters use either electricity or a combustible fuel to heat a supply of water for use on demand by the homeowner. The fuel may include propane or natural gas which is delivered to a combustion chamber proximate the water tank. The fuel is combusted within the combustion chamber to heat and maintain the water at a predetermined temperature. In order to service and deliver fuel to the combustion element, the combustion chamber is typically open to the exterior of the water heater. This may create a path for other gases to reach the combustion element.

Water heater combustion chambers eliminate exterior combustion by utilizing a functionally sealed combustion chamber which controls the gas flow exteriorly of the chamber. The sealed chamber, however, may complicate manufacture and assembly of the water heater. A sealed chamber reduces many of the assembly tolerances between the control unit/regulator and the burner. In addition, the gas supply must pass through a sealed door for delivery of the combustion fuel. One such sealed door includes a flare connection and threaded nut fitting between a gas supply line which extends outside of the combustion chamber and a gas supply tube on the interior. Although effective, the connection components are rather expensive which further increases the per unit water heater manufacturing expense.

SUMMARY OF THE INVENTION

A gas supply coupling for delivering combustion gases to a combustion chamber of a heating device according to an exemplary aspect of the present invention includes a shield adapted to fit within an opening to a combustion chamber; a fitting affixed to the shield; a gas supply tube affixed to the fitting; a gas supply line; and a crimp ring which provides a metal-to-metal seal between the gas supply tube and the gas supply line.

A method of assembling a gas supply coupling for delivering combustion gases to a combustion chamber of a heating device according to an exemplary aspect of the present invention includes: locating a the gas supply tube through the fitting; telescoping the gas supply tube with a gas supply line at an overlap; and connecting the gas supply tube and the gas supply line with a crimp ring at the overlap.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:

FIG. 1 is a general side view of a gas supply coupling for a water heater embodied in the present invention;

FIG. 2A is an exploded view of a fitting for the gas supply coupling;

FIG. 2B is a front view of a plate for the gas supply coupling; and

FIG. 2C is a sectional side view of the fitting of FIG. 2A mounted within an opening defined in the housing of a water heater.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a general perspective view of a gas supply assembly 10 for use with a water heater assembly 12. The water heater assembly 12 includes a water heater housing 14 that may be compartmentalized to include a water tank 16 and a combustion chamber 18. Disposed within the combustion chamber 18 is a burner 20 in close proximity to the water tank 16. The gas supply assembly 10 of the present invention is designed to deliver fuel to the burner 20 for combustion proximate the water tank 16 thereby heating the water within the tank 16 to a predetermined temperature. The gas supply assembly 10 will be connected to a fuel supply F which in the preferred embodiment is natural gas although it is contemplated that the gas supply assembly 10 may be used with other fuel types including propane. The combustion chamber 18 includes an opening 22 to the exterior of the water heater 12 to facilitate access to the gas supply and combustion elements. However, this opening 22 may also form a pathway for foreign elements and gases to reach the burner 20.

The gas supply assembly 10 is disposed within and extends through the opening 22 of the combustion chamber 18. The gas supply assembly 10 includes a bulkhead shield 24 configured to seat within the opening 22 thereby closing this pathway into the combustion chamber 18. Mounted to the shield 24 is a coupling 26 which provides interconnection between a gas supply line 28 and a gas supply tube 30. The gas supply line 28, in one non-limiting embodiment, is a flexible line which is connected to the fuel supply. The gas supply tube 30 is, in one non-limiting embodiment, a rigid tube with an outlet port 32 at the burner 20 for delivering the fuel to the burner 20.

Referring to FIG. 2A, the coupling 26 includes a plate 36 having a stepped outer periphery 38 (FIG. 2B) for receipt into the shield 24 (FIG. 1). The plate 36 has a non-circular profile and is staked or welded into the shield 24 and to the gas supply tube 30, however other attachments may also be utilized.

Referring to FIG. 2C, the gas supply tube 30 receives the gas supply line 28 directly therein in an overlapped or telescoped relationship at an interface section 40. It should be understood that other male/female receipt arrangements may also be utilized.

A crimp ring 42 provides a metal-to-metal seal between the supply tube 30 and the gas supply line 28 at the interface section 40. One such crimp ring 42 may be a crimp ring manufactured by Lokring of Bartow, Fla. The crimp ring 42 provides contact stresses which are sufficiently high to plastically yield a portion of the interface section 40 between the gas supply tube 30 and the gas supply line 28 forming a circumferential, permanent, metal-to-metal seal. The crimp ring 42 facilitates a permanent joint and avoids the usage of elastomeric or rubber seals, O-rings or gaskets which may degrade and leak over time. The crimp ring 42 essentially meets all criteria of a welded connection, except that no heat is required to make the connection.

It should be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit from the instant invention.

Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present invention.

The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention. 

1. A gas supply coupling for delivering combustion gases to a combustion chamber of a heating device, said supply coupling comprising: a shield adapted to fit within an opening to a combustion chamber; a fitting affixed to said shield; a gas supply tube affixed to said fitting; a gas supply line; and a crimp ring which provides a metal-to-metal seal between said gas supply tube and said gas supply line.
 2. The gas supply coupling as recited in claim 1, wherein said fitting includes a stepped non-circular perimeter braised into said shield.
 3. The gas supply coupling as recited in claim 1, wherein said gas supply tube is received at least partially within said gas supply line.
 4. The gas supply coupling as recited in claim 1, wherein said gas supply line is received at least partially within said gas supply tube.
 5. The gas supply coupling as recited in claim 1, wherein said gas supply line and said gas supply tube are in a telescoped relationship along an interface section.
 6. The gas supply coupling as recited in claim 5, wherein said coupling is located at said interface section.
 7. The gas supply coupling as recited in claim 1, wherein said gas supply line is flexible.
 8. A water heater assembly comprising: a water heater housing having an opening; a shield adapted to fit within said opening; a fitting affixed to said shield; a gas supply tube affixed to said fitting; and a gas supply line; a crimp ring which provides a metal-to-metal seal between said gas supply tube and said gas supply line.
 9. The water heater assembly as recited in claim 8, wherein said water heater housing is compartmentalized to include a water tank and a combustion chamber.
 10. The water heater assembly as recited in claim 9, further comprising a burner within said combustion chamber adjacent said water tank.
 11. The water heater assembly as recited in claim 8, wherein said gas supply line is flexible. 